1. Technical Field
The present invention relates generally to data communications.
2. Description of the Background Art
Power amplifiers are typically used to amplify signals for wireless transmission. For example, remote radio heads (RRHs) use power amplifiers to amplify analog signals which are transmitted over the air to implement 2G, 3G, 4G, and other wireless networks.
Signal distortion caused by the power amplifier's nonlinearity is often compensated by using a predistortion technique. Predistortion involves distorting initial signals before supplying them to the amplifier such that the distortion of the power amplifier will null the predistortion, where the predistortion may be approximately an inverse of the distortion of the power amplifier. In this manner, amplified signals can be generated with signal characteristics linear to the original signal. The predistortion is typically performed in the digital domain just before the digital-to-analog conversion that is used to generate the analog signals which are supplied to the power amplifier for amplification.